https://excalidraw.com/#room=9f348f0b46dc752f1ad3,Bm8dWDThu2HW_EEHXDfiLQ

https://www.bcoi.cn/d/hgjs/blog/566

ios::sync_with_stdio(false);

---
```echarts
#include <bits/stdc++.h>
using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;

    string base;
    cin >> base;

    for (int i = 2; i <= n; i++) {
        string s;
        cin >> s;
        if (base.back() == s.front()) {
            base += s.substr(1);
        }
    }

    cout << base << ' ';

    return 0;
}